Calibration of a line driving device

Abstract

Method, arrangement and devices for calibration of a line driving device, such as a DSLAM, having a line port. The method comprises deriving of a first parameter vector, PVinf, for example Hinf. The parameter vector PVinf is derived by performing, at a first site, an echo measurement on the line driving device while the line port on said line driving device is open. The method further comprises calibrating the line driving device based on the first parameter vector PVinf and a second parameter vector PVref, which second parameter vector is based on information on echo measurements performed on at least one reference line driving device.

The invention claimed is: 
     
       1. A method for calibration of a line driving device having a line port, the method comprising:
 deriving a first parameter vector (PVinf) by performing, at a first site, an echo measurement on the line driving device while the line port on said line driving device is an open-circuit; 
 calibrating the line driving device based on the first parameter vector and a second parameter vector (PVref), which second parameter vector is based on information on echo measurements performed on at least one reference line driving device. 
 
     
     
       2. The method according to  claim 1 , further comprising:
 estimating the second parameter vector (PVref) further based on the first parameter vector (PVinf). 
 
     
     
       3. The method according to  claim 1 , wherein the information relates to at least one of:
 a parameter vector representing echo characteristics of a reference line driving device having the line port connected to a known load; 
 a mean value of parameter vectors representing echo characteristics of a set of reference line driving devices having the line port connected to a known load; 
 a mean value of parameter vectors representing echo characteristics of a set of reference line driving devices having an open-circuit line port; and 
 a relation between echo characteristics of a set of reference line driving devices having an open-circuit line port, and echo characteristics of the set of reference line driving devices having the line port connected to a known load. 
 
     
     
       4. The method according to  claim 3 , wherein the known load is one of:
 a short circuit; 
 a reference impedance (Zref). 
 
     
     
       5. The method according to  claim 1 , wherein the information is obtained from a control node in a communication system in which the line driving device is to operate. 
     
     
       6. The method according to  claim 1 , wherein said first site is a site where the line driving device is to be located during operation in a communication system. 
     
     
       7. The method according to  claim 6 , wherein the method is performed during device installation. 
     
     
       8. The method according to  claim 1 , wherein said first site is a site where the line driving device is manufactured. 
     
     
       9. The method according to  claim 1 , wherein the second parameter vector (PVref) is based on information on measurements which are performed at a second site, which is different from the first site. 
     
     
       10. An arrangement in a communication system, for calibration of a line driving device having a line port, the arrangement comprising:
 at least one microprocessor; and 
 a non-transitory computer-readable storage medium, coupled to said at least one microprocessor, wherein said non-transitory computer-readable storage medium further includes computer-readable instructions, when executed by said at least one microprocessor, are configured to:
 derive a first parameter vector (PVinf) by performing an echo measurement on the line driving device while the line port on said line driving device is an open-circuit, and 
 calibrate the line driving device based on the first parameter vector and a second parameter vector (PVref), which second parameter vector is based on information on echo measurements performed on at least one reference line driving device. 
 
 
     
     
       11. The arrangement according to  claim 10 , wherein said computer-readable instructions, when executed by said at least one microprocessor, are further configured to:
 estimate the second parameter vector (PVref) further based on the first parameter vector (PVinf). 
 
     
     
       12. The arrangement according to  claim 10 , wherein the information relates to at least one of:
 a parameter vector representing echo characteristics of a reference line driving device having the line port connected to a known load; 
 a mean value of parameter vectors representing echo characteristics of a set of reference line driving devices having the line port connected to a known load; 
 a mean value of parameter vectors representing echo characteristics of a set of reference line driving devices having an open line port; and 
 a relation between echo characteristics of a set of reference line driving devices having an open-circuit line port, and echo characteristics of the set of reference line driving devices having the line port connected to a known load. 
 
     
     
       13. The arrangement according to  claim 12 , wherein the known load is one of:
 a short circuit; 
 a reference impedance (Zref). 
 
     
     
       14. The arrangement according to  claim 10 , further comprising computer-readable instructions, when executed by said at least one microprocessor, are configured to:
 obtain said information from a control node in a communication system in which the line driving device is to operate. 
 
     
     
       15. Line driving device comprising an arrangement according to  claim 10 . 
     
     
       16. Digital Subscriber Line Access Multiplexer comprising an arrangement according to  claim 10 . 
     
     
       17. A non-transitory computer-readable storage medium, further including computer-readable instructions, when executed by at least one microprocessor, are configured to:
 derive a first parameter vector (PVinf) by performing an echo measurement on the line driving device while the line port on said line driving device is an open-circuit, and 
 calibrate the line driving device based on the first parameter vector and a second parameter vector (PVref), which second parameter vector is based on information on echo measurements performed on at least one reference line driving device. 
 
     
     
       18. The non-transitory computer-readable storage medium according to  claim 17 , wherein the computer-readable instructions, when executed by the at least one microprocessor, are further configured to:
 estimate the second parameter vector (PVref) further based on the first parameter vector (PVinf). 
 
     
     
       19. The non-transitory computer-readable storage medium according to  claim 17 , wherein the information relates to at least one of:
 a parameter vector representing echo characteristics of a reference line driving device having the line port connected to a known load; 
 a mean value of parameter vectors representing echo characteristics of a set of reference line driving devices having the line port connected to a known load; 
 a mean value of parameter vectors representing echo characteristics of a set of reference line driving devices having an open line port; and 
 a relation between echo characteristics of a set of reference line driving devices having an open-circuit line port, and echo characteristics of the set of reference line driving devices having the line port connected to a known load. 
 
     
     
       20. The non-transitory computer-readable storage medium according to  claim 17 , wherein the known load is one of:
 a short circuit; 
 a reference impedance (Zref).